prevent crash of TestContext in case no tests were enabled / found in test.cfg
prevent crash of TestContext in case no tests were enabled / found in test.cfg

--HG--
branch : v1-9

jhu-lcsr-forks/ogre,jhu-lcsr-forks/ogre,jhu-lcsr-forks/ogre,jhu-lcsr-forks/ogre,jhu-lcsr-forks/ogre